It's great that coffee shops offer free Wi-Fi to customers, but many are starting to employ time limits to limit how long you spend in their establishments. If you want to hang out longer than allowed, these time limits aren't that hard to circumvent. According to security expert Brandon Gregg, you just need to spoof your MAC address.

Basically, the process is pretty simple. You just need an app like MAC Makeup so you can spoof a new MAC address and continued Wi-Fi access will be yours. Even changing a single number should do the trick. Brandon also offers up a slightly more devious solution:

An even better trick is use your Wi-Fi to sniff (with an app like Cain & Able, http://www.metageek.net/products/inssi..., NetStumbler) other laptops' Wi-Fi MAC addresses already using the paid coffee shop Wi-Fi. Once you find a few you can copy their mac address as your own. This will give you free Wi-Fi in hotels and other paid Wi-Fi locations.

This, of course, assumes that the paid Wi-Fi locations are owned by the same company and don't require a login. While we don't recommend stealing access, this is a good trick to have up your sleeve if you're in a bind or just need to extend your time limit at your favorite coffee shop.